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Here's a question:

I'm daydreaming about a homebrew project which would have VRC7 audio. Easy enough in an emulator, but I'd like to be able to make some game cartridges out of it, and there's no way I'd sacrifice a Lagrange Point cartridge for the silly little game I have in mind. So the other option is to sacrifice a Japanese Tiny Toon Adventures 2 cartridge, a significantly less colossal loss. This wouldn't have any negative effects on the game, which would do just fine with CHR-ROM, doesn't need SRAM, and would definitely fit in 128KB PRG-ROM and 128KB CHR-ROM. My only question is this: TTA2 (J) doesn't use the VRC7 audio, but the audio generator's still present in the cartridge, right? Or is the sound expansion a separate chip which is present in Lagrange Point but not TTA2?

I'm not sure because I don't have either cart, but the sound stuff might still be on the chip, but I think you'll need a DAC and need to mix the Famicom channels in too. With the board mods needed, and if TTA2 turns out to be rare enough, it might be easier to make a new board and find a source for Yamaha chips. I doubt you could find the same type as VRC7, but there are a lot of similar ones.

I have both carts; Tiny Toons 2 is a regular size Konami cart, Lagrange is an oversized cart. I bet TT2 doesn't have at least the audio circuit if not the external IC (if that's the case); that or it's an entirely different ASIC only operationally similar to the VRC7. Also, I paid about twice as much for Tiny Toons 2 ($16) as I did for Lagrange ($9) in a Tokyo used gameshop, I think Japanese eBay shops will charge accordingly to what they buy the carts for.

Also remember that Konami carts snap together only so they won't be the cleanest to open (or else I'd check for you) :)

I just got my Lagrange Point cartridge yesterday, and I concur. Not only is it taller than a normal Famicom cartridge, it's noticeably heavier, so I'm almost certain that the sound is on its own IC. When AGTP finally finishes the translation and I have to open it up to make a translated cart I'll know for sure

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I just got my Lagrange Point cartridge yesterday, and I concur. Not only is it taller than a normal Famicom cartridge, it's noticeably heavier, so I'm almost certain that the sound is on its own IC.

My Just Breed cart is also somewhat taller and hevier than anyother famicom game (I had to trick to be able to instert it at all with a honeybee adaptater, wich normally just wouldn't fit a NES). However, the sound is intergreated to the MMC5.
Maybe the VRC7 sound is external trough, because Tiny Toon Adventures II made absolutely no use of it, so maybe the cart just does lack that IC. It acually look just identical to the MMC3 counterpart, making me ask myself why they bothered using VRC7 at all.

Sound definitely is in the VRC7 chip, but if the TT2 cart is the same version of that chip is the unknown thing (seems like it would be). I've seen the Lagrange Point PCB, it was several years back though.

It acually look just identical to the MMC3 counterpart, making me ask myself why they bothered using VRC7 at all.

Possibly:
They had a bunch of VRC7 chips they needed to use, and had experience with it.
They thought it'd sell better in the US (save development time, obviously they didn't mind for CV3 though). Don't know about in Japan, but that show was hugely popular back when I was in middle school. Yet I've never seen the cart (or even the first one).
Analogue stuff needs more materials and labor, but you can't charge the same higher price for a platformer compared to an RPG (Lagrange Point) or hit sequel (CV3).

so I'm almost certain that the sound is on its own IC

Nope. It's all in the mapper. (which is a big 48-pin PDIP)

They had a bunch of VRC7 chips they needed to use, and had experience with it.

That's nonsense, since they had to port the code to the MMC3 to export the thing to the U.S.

They thought it'd sell better in the US (save development time, obviously they didn't mind for CV3 though).

Maybe so, but they definitely mind for CV3. I think the music was first composed for a normal chip and then ported to the VRC6. They just used the normal music on the MMC5 version. Why ? Becuase the additionnal VRC6 channels plays almost the same thing as the normal NES channels, and the normal NES channels play echoes sound to the main channels or just additional harmonics. Also, I think they developped CV3 with the MMC5 port in mind all the way, because due to how well CV1 and 2 sold worldwide, they most probalby cared about the port. Just compare CV3 (japanese) with other VRC6 games such as Mouryou Senki Madara (J).
Some other games, like Just Breed obvioulsy could just never be ported to the outside without some very serious downgrade to the soundtrack.

Something to note:

NESdevWiki:Konami VRC7#Registers wrote:One variant of the VRC7 uses A4 for registers ($x010), another uses A3 ($x008). Additionally, A5 is used on the first mentioned variant only for sound registers ($x030)

Clarification: My point is that Lagrange Point and TTA2j must at least have different wirings (and possibly different revisions of the VRC7 chip, although I'm not sure whether that matters).

I found a picture of Lagrange's board:



The "counter" is of course WRAM.

I saw a MontanaLand He Youkosou pcb image quite a while ago, and I can confirm that the sound hardware was not available, but may have still been in chip.

These board share the same kind of relationship that Gradius II shares with other vrc carts in it's series, where small wiring changes were made for pratically unknown reasons then manufactured accordingly. Waste of mappers if you ask me...I personally just wish UNIF would kill iNes. C'mon...how long has AIFF been around, and still used...

I'll see if I can find the picture...can't confirm that I'll find it, but it was missing the whole mixer IC (that thick glop that kinda looks like an RN).

AWal wrote:These board share the same kind of relationship that Gradius II shares with other vrc carts in it's series, where small wiring changes were made for pratically unknown reasons then manufactured accordingly.

Konami did the same thing on its arcade boards: swapping I/O address lines and using different encryption methods all to keep people from burning a new set of ROMs instead of buying a new PCB.

AWal wrote:I personally just wish UNIF would kill iNes.

Well, we all hope that NES2.0 will steal the show...

hi.
anybody have TT2j catridge PCB photo??

kyuusaku wrote:I found a picture of Lagrange's board:



The "counter" is of course WRAM.

Hmm, looks like there isn't a separate sound chip after all. Of course, that doesn't preclude TTA2 being a different chip with the same mapper scheme but no sound, but still, good news.